Contact breakers for engine ignition systems



Dec. 19, 1961 G. A. GAYLER 3,014,101

CONTACT BREAKERS FOR ENGINE IGNITION SYSTEMS Filed Feb. 24, 1959 I8 26'? I INVENTOR L3 MAW A TTORNE-Y United States Patent ()fitice 3,014,101 Patented Dec. 19, 1961 3,014,101 CONTACT BREAKERS FOR ENGINE IGNITION SYSTEMS George Alfred Gayler, Bletchley, England, assignor to Wipac Development Limited, London, England, a British company Filed Feb. 24, 1959, 'Ser. No. 795,901 Claims priority, application Great Britain Apr. 18, 1958 3 Claims. (Cl. 200-30) The present invention relates tocontact breakers for engine ignition systems.

Such contact breakers are usually of the type comprising a base, a rocker arm rockably mounted on a pin fixed to the base and carrying a moving contact which co-operates with a fixed contact on the base, and a spring connected between the base and the arm and serving to urge the moving contact into engagement with the fixed contact.

The pin of the rockable mounting usually engages in a bush fixed in the arm, the bush being commonly made of a moulded material. The arm is provided with a heel adapted to engage a cam by which the arm is rocked to open the contacts, this heel also usually of moulded material.

The rocker arm is usually made of metal and difficulties have been experienced owing to the bush and the heel of moulded material working loose. There has also been difi'iculty in maintaining an accurate dimension between the heel and the bush owing to variation in the diameter of rivets used to fasten the heel to the arm and to location tolerances.

Certain contact breakers have been made with a rocker arm of moulded material, the need for a separate bush and heel being thus avoided, but known contact breakers of this kind have been less compact than would be desirable.

The present invention has for its principal object to provide an improved contact breaker in which the difiiculties referred to are avoided and which can, nevertheless, be made at least as compact as known contact breakers with metal rocker arms.

According to the present invention there is provided a contact breaker for an engine ignition system of the type set forth, in which the rocker arm is of moulded material having the heel formed integral therewith, the pin fixed to the base engaging in an aperture in the arm without the intermediary of a separate bush, and the spring having one end fixed to the base, extending through an aperture in the arm from one side of the arm to the other side and having its other end fixed to the said other side of the arm. The said other end of the spring may be fixed to the arm by one or more rivets which also serve to fix the moving contact to the arm.

By arranging that the spring passes through the arm the device can be made compact without the need for an excessively sharp bend in the spring. The arm can be made light and nevertheless stiff by forming it with relatively deep flanges.

The invention will be described, by way of example, with reference to the accompanying drawings in which FIGS. 1 and 2 are enlarged views in plan and side elevation respectively of one embodiment of the invention, and

FIG. 3 is a view in section on the line 33 of FIG. 2.

In the drawing the contact breaker shown has a metal base 10 having a fixed contact 11 riveted to 8. lug 12 bent up from the base. An arm 13 of moulded insulating material is mounted on a pin 14 fixed to the base which is a working fit in an aperture in the arm. A conductive plate 15 having a moving contact 16 riveted to one end is fixed to the arm 13 by rivets 17, 18. The rivet 17 serves also to clamp one end of a metallic or otherwise electrically conductive spring 19 (which in this example is formed of two flat springs) which is smoothly curved with the radii of all points of curvature lying on one side thereof and passes through an aperture 20 in the arm. The other end of the spring is fixed by means of a bolt 21 in an insulating block 22 which is supported between forked ends 23, 24 of a lug 25 bent up from the base 10. The arm has a heel 26 formed integral therewith.

As best seen in FIG. 2, the arm is of light but stiff construction having two side checks or flanges 27, 23 bounding a channel of a width adapted to receive the spring 19.

I claim:

1. A contact breaker for an engine ignition system comprising: a base, a fixed contact member on said base; a rocker arm of moulded insulating material pivotally mounted on said base on an axis substantially perpendicular to said base, said arm being formed having an aperture therein; a movable contact member engageable with said fixed contact member; a metallic spring fixed at one end to said base, passing through said aperture and hav ing its other end fixed to said rocker arm, said spring being smoothly curved with the radii of all points of curvature lying on one side thereof; and a conductive plate carrying said movable contact member, said plate being fixed to said rocker arm and overlying said other end of said spring.

2. A contact breaker according to claim 1, wherein said rocker arm is formed with two side cheeks between which said spring is fixed.

3. The contact breaker recited in claim 1 in which said conductive plate is fixed to said rocker arm by rivets, at least one rivet passing through said rocker arm, said spring and said plate.

References Cited in the file of this patent UNITED STATES PATENTS 2,173,828 Doran Sept. 26, 1939 2,316,156 Doran Apr. 13, 1943 2,435,128 Carlson Jan. 27, 1948 2,794,102 Tollefsen et al. May 28, 1957 2,851,546 Phelon et al. Sept. 9, 1958 

